Copy missing QML libraries from VCPKG buildenv on Windows and macOS

[JoergAtGithub]

Feature Description

I got the QML UI working on Windows, by using the buildenv from Main and copying the following files

.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6LabsQmlModels.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QmlWorkerScript.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QuickControls2.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QuickControls2Impl.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QuickLayouts.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QuickShapes.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6QuickTemplates2.dll
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\bin\Qt6ShaderTools.dll

and directories

.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\Qt6\qml\Qt
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\Qt6\qml\Qt5Compat
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\Qt6\qml\QtQml
.\mixxx-deps-2.5-x64-windows-32f6f03\installed\x64-windows\Qt6\qml\QtQuick

to my build directory.

[Holzhaus]

Are we sure that this isn't a bug in the vcpkg package? We should strive to fix this upstream in the portfile rather than adding this to our cmakelists file.

[daschuer]

In Qt6, We need to copy the plugins ourself. This is a weakness but not a bug.

[acolombier]

Note that this issue also appears to impact MacOS

[daschuer]

We currently build Mixxx static on macOS. The Plugins are however loaded at runtime. In a static build they will be discarded. The vcpkg environment does not provide the dynamic builds.
Do you know how it supposed to work?
Do we need to move to dynamic linking on macOS like on windows? Unfortunately this was not working when I last tried it.

[JoergAtGithub]

daschuer:

The deployment of Qt6 has changed. I have tried to implement it but it fails and I give up for now since I am not a Windows developer. https://github.com/daschuer/mixxx/tree/qml6
Instead of fighting the Qt CMake macros that allow to selective install only used dependencies, we may just install the whole folder like it is done on Linux.

Can you point out which folder form the environment is required?

[JoergAtGithub]

I could copy all the files above, by appending the following code to my CMakeLists.txt.
But something is missing again, mixxx --qml doesn't come up with these files.

# The following script must only be executed at install time
set(deploy_script "${CMAKE_CURRENT_BINARY_DIR}/deploy_Mixxx.cmake")

# Generate a deployment script to be executed at post build time
qt_generate_deploy_script(
    TARGET mixxx
    OUTPUT_SCRIPT deploy_script
    CONTENT "
include(\"${QT_DEPLOY_SUPPORT}\")
qt_deploy_qml_imports(
    # Deploy QML modules used by MyApp
    TARGET mixxx

    # The found QML plugins are stored in the plugins_found variable
    PLUGINS_FOUND plugins_found

    # The QML modules will be deployed into a custom directory
    QML_DIR \"qml\"
)
# Deploy application runtime dependencies and runtime dependencies
# of the found QML module plugins.
qt_deploy_runtime_dependencies(
    EXECUTABLE $<TARGET_FILE:mixxx>
    ADDITIONAL_MODULES \${plugins_found}
)
")

add_custom_command(
    TARGET mixxx POST_BUILD
    COMMAND "${CMAKE_COMMAND}" -DCOMPONENT=applocal -DCMAKE_INSTALL_PREFIX="${CMAKE_CURRENT_BINARY_DIR}" -P "${deploy_script}")

[daschuer]

I was not able to use the deploy script successfully. So I added the files manually like it is done in the Linux packages.
#12604 should fix the issue.

[JoergAtGithub]

#12604 copies only a few of the files listed above - and of cause Mixxx can't load the QML UI therefore